diff --git a/pkg/controller/controller_utils.go b/pkg/controller/controller_utils.go
index c3d0716b15..661b71f96a 100644
--- a/pkg/controller/controller_utils.go
+++ b/pkg/controller/controller_utils.go
@@ -717,7 +717,8 @@ func GetFakeMachineFromTemplate(template *v1alpha1.MachineTemplateSpec, parentOb
 	desiredAnnotations := getMachinesAnnotationSet(template, parentMetaObj)
 
 	prefix := getMachinesPrefix(parentMetaObj.GetName())
-	prefix = prefix + "-" + uuid.New().String()[:5]
+	// Use the full UUID as the suffix to avoid name collisions when many machines are created in a single reconcile.
+	prefix = prefix + "-" + uuid.New().String()
 	machine := &v1alpha1.Machine{
 		ObjectMeta: metav1.ObjectMeta{
 			Labels:      desiredLabels,
diff --git a/pkg/controller/deployment_test.go b/pkg/controller/deployment_test.go
index 9bc8e05b69..d6dfe4a8a3 100644
--- a/pkg/controller/deployment_test.go
+++ b/pkg/controller/deployment_test.go
@@ -8,10 +8,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"slices"
 	"strings"
 	"time"
 
 	"github.com/gardener/machine-controller-manager/pkg/util/annotations"
+	labelsutil "github.com/gardener/machine-controller-manager/pkg/util/labels"
 	"github.com/gardener/machine-controller-manager/pkg/util/provider/machineutils"
 	"k8s.io/utils/ptr"
 
@@ -1966,25 +1968,44 @@ var _ = Describe("machineDeployment", func() {
 					return nil
 				},
 			),
-			// flaky test because of reusing same testMachine for mutilple tests.
 			Entry("should set MachinePriority=1 for the machines named in TriggerDeletionByMCM annotation in the MachineDeployment",
-				func(testMachineDeployment *machinev1.MachineDeployment, _ *machinev1.MachineSet) {
+				func(testMachineDeployment *machinev1.MachineDeployment, testMachineSet *machinev1.MachineSet) {
 					testMachineDeployment.Annotations[machineutils.TriggerDeletionByMCM] = fmt.Sprintf("%s~%s", testMachine.Name, time.Now().Format(time.RFC3339))
+					testMachineSet.Spec.Selector = labelsutil.CloneSelectorAndAddLabel(testMachineSet.Spec.Selector, machinev1.DefaultMachineDeploymentUniqueLabelKey, "testhash")
 				},
 				func(_ *machinev1.MachineDeployment, _ []machinev1.MachineSet, machines []machinev1.Machine, _ *corev1.Node) error {
-					Expect(machines[0].Annotations[machineutils.MachinePriority]).To(Equal("1"))
+					idx := slices.IndexFunc(machines, func(m machinev1.Machine) bool {
+						return m.Name == "Machine-test"
+					})
+					if idx == -1 {
+						return errors.New("machine \"Machine-test\" not found")
+					}
+					if machines[idx].Annotations[machineutils.MachinePriority] != "1" {
+						return errors.New("expected MachinePriority=1 on machine \"Machine-test\"")
+					}
 					return nil
 				},
 			),
 			Entry("set LDRCBST annotation on the machineSet and TriggerDeletionByMCM annotation is not set on the machineSet",
-				func(testMachineDeployment *machinev1.MachineDeployment, _ *machinev1.MachineSet) {
+				func(testMachineDeployment *machinev1.MachineDeployment, testMachineSet *machinev1.MachineSet) {
 					testMachineDeployment.Annotations[machineutils.LastDeploymentReplicaChangeByScalerTime] = ts
 					testMachineDeployment.Annotations[machineutils.TriggerDeletionByMCM] = fmt.Sprintf("%s~%s", testMachine.Name, time.Now().Format(time.RFC3339))
+					testMachineSet.Spec.Selector = labelsutil.CloneSelectorAndAddLabel(testMachineSet.Spec.Selector, machinev1.DefaultMachineDeploymentUniqueLabelKey, "testhash")
 				},
 				func(_ *machinev1.MachineDeployment, mcs []machinev1.MachineSet, _ []machinev1.Machine, _ *corev1.Node) error {
-					Expect(mcs[0].Annotations[machineutils.LastDeploymentReplicaChangeByScalerTime]).To(Equal(ts))
-					_, exists := mcs[0].Annotations[machineutils.TriggerDeletionByMCM]
-					Expect(exists).To(BeFalse())
+					idx := slices.IndexFunc(mcs, func(ms machinev1.MachineSet) bool {
+						return ms.Name == "MachineSet-test"
+					})
+					if idx == -1 {
+						return errors.New("machineSet \"MachineSet-test\" not found")
+					}
+					ms := &mcs[idx]
+					if ms.Annotations[machineutils.LastDeploymentReplicaChangeByScalerTime] != ts {
+						return errors.New("expected LastDeploymentReplicaChangeByScalerTime annotation to be preserved on the machineSet")
+					}
+					if _, exists := ms.Annotations[machineutils.TriggerDeletionByMCM]; exists {
+						return errors.New("TriggerDeletionByMCM annotation should not be set on the machineSet")
+					}
 					return nil
 				},
 			),